This invention relates to an applicator tool for manual delivery of a controlled quantity of a selected adhesive material to an application site.
In construction of models, such as model aircraft and ships made from wood and plastic, it is common to employ a cyanoacrylate (CA) adhesive for bonding the components of the model. CA adhesive is favorable for this purpose, because when it is of low viscosity, its surface tension causes the adhesive to wick readily between two components that are held close together.
CA adhesive is usually sold in small bottles with a dispensing nozzle, but the dispensing nozzle is rather thick and may only be about 3 cm long, so that interference from components that have previously been assembled renders it difficult to position the tip of the nozzle sufficiently close to the location at which a joint is desired for the drop of adhesive to span the joint so that the adhesive will wick between the two components. Further, it is virtually impossible to control the size of the drop sufficiently precisely to ensure that enough adhesive is delivered to secure the components without forming an objectionable fillet. Moreover, the material of the nozzle is such that any adhesive that drips down the exterior of the nozzle and becomes cured adheres strongly to the nozzle so that it is very difficult to remove. Consequently, the nozzle becomes thickened and the difficulty of placing the tip of the nozzle at the desired location is exacerbated.
The problem of accurately delivering a liquid to an application site arises not only with adhesives but also with other liquids, such as paints and lubricating oils. It is conventional to use a brush to apply paint to a solid object. When a brush is used, there is a danger that a bristle will become detached from the brush and mar the painted surface. A dropper, comprising a nozzle with a suction bulb attached, may be used to deliver lubricating oil to an application site, but frequently the smallest drop that can be deposited using a dropper is much larger than is necessary to accomplish the intended purpose.